Question:
The number 64 has the property that it is divisible by its units digit. How many whole numbers between 10 and 50 have this property?

Answer:
Twelve numbers ending with 1, 2, or 5 have this property. They are 11, 12, 15, 21, 22, 25, 31, 32, 35, 41, 42, and 45. In addition, we have 33, 24, 44, 36, and 48, for a total of $\boxed{17}$. (Note that 20, 30, and 40 are not divisible by 0, since division by 0 is not defined.)